The instructions are as follows
dfu-util.exe -d 1d6b:0202 -a 0 -D ota.bin

1.It need to install the libusb.
2.After installing the libusb, the device manager will show the usb_dfu_class
3.dfu-util.exe -d 1d6b:0202 -a 0 -D ota.bin